Controller and method for multi-zone air heating and cooling system with motorized vents

ABSTRACT

A method of controlling a zoned, building air heating, cooling or air conditioning system to control the temperature environment of the individual zones without the use of on-demand heating and cooling sources that consume energy includes collecting data from a plurality of zone temperature sensors; monitoring the temperature sensor data in substantially real-time; generating a trigger signal when zone temperature sensor data is different from predefined zone temperature sensor threshold values; ranking the plurality of temperature-controlled zones based at least on the difference between the real-time zone temperature and the predefined zone temperature sensor threshold value; and adjusting the opening and closing of a plurality of motorized air ventilation ports in the zones according to the rankings of the zones, and activating a fan that moves air between the zones that have open ventilation ports, when the trigger signal is present.

CROSS-REFERENCE TO RELATED APPLICATION

This application is related to and claims priority to U.S. ProvisionalPatent Application Ser. No. 62/179,071, filed Apr. 28, 2015, entitled“CONTROLLER AND METHOD FOR MULTI-ZONE AIR HEATING AND COOLING SYSTEMWITH MOTORIZED VENTS”, the entirety of which is incorporated herein byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

n/a

TECHNICAL FIELD

This invention relates generally to heating, ventilation, and airconditioning (HVAC) systems and more particularly to computer and remotecontrol of motorized air vents and air heating and cooling sources.

BACKGROUND

In residential HVAC systems, and particularly in smaller homes, it iscommon to install the entire HVAC system as one zone with one controlthermostat for installation cost savings and ease of installation. It ishowever difficult to maintain a desired temperature environment in allrooms in such systems.

If it is desired to maintain the same temperature environment in allrooms, the resident may manually adjust individual room air vents in anattempt to balance the amount of heat or cooling provided from theheated or cooled air coming from the heating or cooling source. However,depending on the time of day, the amount sunlight coming in, thetemperature outside, and other factors, this balancing may be reasonablyeffective in some circumstances and entirely ineffective at other times.If it is desired to maintain different temperatures in individual rooms,this imbalance problem is exacerbated further because the thermostatcontrol exists only in one location, perhaps not even near a vent. Forthese reasons some rooms become overheated, some under-heated, and thissituation changes in a generally uncontrollable manner.

It is therefore desirable to provide zoning to HVAC systems such thateach designated zone has individual control over the local temperature.If provided, such zoned systems are normally installed in the initialsystem by placing motorized dampers in the ducts leading to the vents,the dampers being under the control of multiple thermostats. In suchsystems, any thermostat may call for heating and/or cooling at any time.However, retrofitting an existing single-zone system to become amulti-zone system can be problematic because of the need to runs wires,retrofit dampers in the walls or ceilings of ductwork; further,retrofitting even if feasible, can be expensive.

It is therefore desirable to provide a means of inexpensivelyretrofitting a single-zone system to create a multi-zone system withoutrunning wires or installing intra-duct dampers. Several systems existthat provide some degree of functionality aimed at such retrofits forindividual zoning of HVAC systems. One such system provides closing ofvents in rooms that are being overheated in the winter and/or overcooledin the summer according to the temperature in the room as measured by atemperature measuring device in the room. However this system stillrelies on the same, originally installed single thermostat to create aheating or cooling call and therefore cannot arbitrarily heat a coldroom or cool a hot room. It is therefore desirable to provide zoning toHVAC systems such that each designated zone has individual control overthe local temperature by: a) closing vents in rooms that are beingoverheated in the winter and/or overcooled in the summer, and b) bycausing the heating or cooling system to turn on according to thetemperature in any individual room zone independent of a “central”thermostat. It is desirable to create a multi-zone heating and coolingsystem that can be retrofitted to a single zone system wherein any zonecan call for heating or cooling and can also limit the heating andcooling of a particular zone when other zones require the system to beon.

In HVAC systems, a fan is used to provide distribution of the heating orcooling through the air vents. If many vents are partially or completelyclosed, the running of the fan may cause an undesirable back pressurewhen operating. This results in hot or cool air leakage intouncontrolled spaces in walls and between floors, and can also cause“whistling” noise from partially closed vents because of increased airflow velocity. For this reason, existing retrofit multi-zone systemswith motorized vents will sometimes recommend that not every vent in thesystem be automated so that the back pressure is never so great as tocause a problem. This restriction partially defeats the primary reasonfor having the multi-zone system in the first place, because not everyvent is controlled. It is therefore desirable to create a multi-zoneheating and cooling system wherein the undesirable air leakage and noiseis prevented by controlling against too much backpressure throughcontrolling the number of vents that are completely closed and/orcontrolling the fan speed.

In HVAC systems, when a zone is too cold during the heating season, ortoo hot during the cooling season, the fan is turned on and a heating orcooling source is also activated. These heating and cooling sources arethe main users of energy in such systems. However, at times in theheating season, for example, there are rooms that are too cold andsimultaneously there are rooms that are warmer than their thermostatsetpoints. In such a case, in order to save energy, it would bedesirable to have intelligent control of the vents and the fan such thatthe system could, by selective opening and closing of vents and turningon of the fan, move warm air from some of the warmer rooms to some ofthe colder rooms, without turning on the heating source. Similarly, incooling season, the system could move cool air from some of the coolerrooms to some of the warmer rooms by controlling vents and the fan,without turning on the cooling source.

In large buildings and commercial installations, it is not uncommon tohave some rooms that are too hot almost all of the time, and other roomsthat are too cool almost all of the time. In such situations, controlschemes for a multi-zone HVAC system similar to that described abovecould be used to lower energy costs by using waste heat from the warmrooms to warm the cold rooms, or vice versa, to use waste cooling fromthe cool rooms to lower the temperature in too-warm rooms, all withoutcausing the heating or cooling source to operate.

SUMMARY

The present invention advantageously provides for a building airheating, cooling and air conditioning (HVAC) system including aplurality of temperature-controlled zones, each zone with at least onemotorized air ventilation port. At least one of a heating source and acooling source is included, the at least one of the heating source andthe cooling source includes a fan fluidly connected to the ventilationports with air ducts. A plurality of zone temperature sensors sourcepositioned to measure the air temperatures in the plurality oftemperature-controlled zones are included. At least one return-air portis fluidly coupled to at least one of the heating source and the coolingsource. A controller is in communication with the plurality of motorizedair ventilation ports, the plurality of zone temperature sensors, andthe at least one of the heating source and the cooling source, thecontroller includes a sensor interface configured to communicate withthe plurality of temperature-controlled zones; a plurality of sensorsconfigured to receive zone temperature sensor data; a monitoring moduleconfigured to monitor the zone temperature sensor data in substantiallyreal-time; a trigger module configured to generate a trigger signal whenthe zone temperature sensor data is different from a predefined zonetemperature sensor threshold value; a ranking module configured to rankthe plurality of temperature-controlled zones based at least on thedifference between the real-time zone temperature and the predefinedzone temperature sensor threshold value; an actuator module configuredto communicate with the trigger module and the ranking module andconfigured to generate control signals to adjust the opening and closingof the plurality of air ventilation ports according to the rankings ofthe temperature-controlled zones and activate the at least one of theheating source and the cooling source and the fan.

In yet another embodiment, the controller of the HVAC system thatcommunicates with a plurality of motorized air ventilation ports, aplurality of zone temperature sensors, and an on-demand heating orcooling source including a fan includes a sensor interface configured tocommunicate with the plurality of zone temperature sensors to receivezone temperature sensor data; a monitoring module configured to monitorzone temperature sensor data in substantially real-time; a triggermodule configured to generator a trigger signal when the zonetemperature sensor data is different from predefined zone temperaturesensor threshold value; a ranking module configured to rank theplurality of temperature-controlled zones based at least on thedifference between the real-time zone temperature and the predefinedzone temperature sensor threshold value; an actuator module configuredto communicate with the trigger module and the ranking module andgenerates control signals to adjust the opening and closing of theplurality of air ventilation ports according to the rankings of thetemperature-controlled zones and activate the at least one of theheating source and the cooling source and the fan.

In yet another embodiment, a method of controlling a zoned, building airheating, cooling or air conditioning system to control the temperatureenvironment of the individual zones without the use of on-demand heatingand cooling sources that consume energy includes collecting data from aplurality of zone temperature sensors; monitoring the temperature sensordata in substantially real-time; generating a trigger signal when zonetemperature sensor data is different from predefined zone temperaturesensor threshold values; ranking the plurality of temperature-controlledzones based at least on the difference between the real-time zonetemperature and the predefined zone temperature sensor threshold value;and adjusting the opening and closing of a plurality of motorized airventilation ports in the zones according to the rankings of the zones,and activating a fan that moves air between the zones that have openventilation ports, when the trigger signal is present.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 illustrates wireless and wired communications components of anexemplary heating and cooling system according to one embodiment of theinvention;

FIG. 2 illustrates the air ducting connections and open/closedconditions of the vents for one particular heating situation for anexemplary system according to one embodiment of the invention;

FIG. 3 illustrates a flow chart for controlling opening and closing ofvents and operation of the heating and cooling sources for the systemcontroller according to one embodiment of the invention; and

FIG. 4 illustrates the air ducting connections and open/closedconditions of the vents for a particular cooling situation for anexemplary system incorporating outside air intake according to oneembodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 illustrates the communications channels of a typicalconfiguration for an air heating or cooling system according to oneembodiment of the invention. Items 10 through 1N are motorized airdiffusion vents in temperature controlled zones, those zones beingmonitored and controlled in part by wireless thermostats, 21 through 2N.Each thermostat is in wireless communications, 51 through 5N with thevent for that zone. In this example, each zone has only one vent, but inmany systems there may be more than one vent in a zone. In that case,the thermostat for each such zone communicates with all the vents inthat zone. The thermostats are also in wireless communication with thesystem central controller 31. Although the communications set forth inthis example are wireless, any of the wireless communications channelscould be replaced by a wired communications channel without altering thefundamental functioning of the communications.

System central controller 31 is in wired communication 32 with theheating or cooling source 41, which itself includes a fan 42. In apreferred embodiment, the fan may be separately controlled from theheating or cooling function. For example, an air furnace may have inputconnections for turning on and off the fan to create air movement, andseparate input connections for turning on and off the burner to produceheat.

FIG. 2 illustrates the duct work for directing the air movement in anexemplary system with three zones. The illustration presents the systemat a particular time when there is heat being delivered to two zonesthrough motorized vents 10 and 11 from the heat source 41 via ductwork101. Motorized vent 12 is closed because that zone does not need heat.According to one embodiment of the invention, the central controllerincludes a computer which collects temperature and thermostat data fromthe zone thermostats, and ranks them according to how far from thethermostat setpoint (“temperature sensor threshold value” in the claims)the temperature in the room actually is. For example, the thermostat forthe zone covered by vent 10 may be set to 70 degrees and the zonetemperature is 65 degrees. The difference for that zone, for purposes ofranking is 5 degrees and the zone is presenting a “call for heat.” Atthe same time, the difference for the zone covered by vent 11 may be,for example, 2 degrees, presenting another call for heat, and thedifference for the zone covered by vent 12 may be −3 (the zone is warmerthan the thermostat setpoint) and the zone is not presenting a call forheat. The central controller 31 is programmed to therefore rank thezones and open the motorized vents such that vent 10 is open more thanvent 11 according to the ranking, and to leave vent 12 closed, alsoaccording to the ranking, and to turn on the heat source 41 and fan 42.Thereby, more heat is delivered to the zone covered by vent 10 than tothe zone covered by vent 11 and no heat is delivered to the zone coveredby vent 12. This ranking and partial opening of vents according toranking will have the consequence of decreasing the furnace runtimebecause heat is being delivered in accordance with a zone's need for it,as determined by the ranking. The controller is further programmed torepeat the data collection and ranking cycle on a regular time intervalas heat is being delivered, in order to adjust the vent openingsdynamically as the zones warm up. The goal is to have each of the zonespresenting a call for heat reach its thermostat setpoint atapproximately the same time.

FIG. 2 in combination with FIG. 3 can also be used to illustrate anothercapability of the invention. Consider a particular time when the zonecovered by vent 10 has a significant negative ranking (e.g., −10,meaning the zone is 10 degrees hotter than the thermostat setpoint).This could be, for example, due to sunlight entering the room in thelate afternoon and warming the zone considerably. At the same time,there may be another zone, say the zone covered by vent 11, which isbelow its thermostat setting and thus may have a ranking of 5 and bepresenting a call for heat. According to one embodiment of theinvention, the central controller 31 is programmed to recognize asituation wherein at least one zone has a significant negative rankingand at least one zone has a positive ranking. In this scenario, thecontroller is further programmed to adjust the motorized vents such thatvent 10 and vent 11 are both opened fully, while vent 12 is kept closed,and to turn on only the fan 42, keeping the heating function of the heatsource 41 turned off. By doing this, the return air streams from the twozones with open vents (10 and 11) are mixed in the return air vent 9 andthe return air ducts 102, and redistributed back to the same two zones.The overall result is the bringing of the two zones towards someintermediary temperature; in other words, the excess heat from the zoneof vent 10 is used to warm the zone of vent 11, without use of electricor other fuel for heating air. Only the electric energy of the fan isutilized.

While the example just given is a demonstration of using excess heat ofone zone to warm another zone, to those skilled in the art, it isobvious that a similar function can be achieved when desiring to coolone zone by using the coolness of another zone and mixing the return airstreams of the two zones with only the system fan 42.

FIG. 4 illustrates another preferred embodiment of the invention whichresults in further energy savings for cooling applications. Consider aparticular time when the zone covered by vent 10 in a building is warmerthan the thermostat setpoint and would normally require the coolingsource and fan to be on and vent 10 to be open. In this embodiment thereare two return-air vents, 9 and 105. Return-air vent 9 allows air frominside the building to return to the cooling source and fan 41 and 42via ducts 102. Return-air vent 105 allows air from outside the buildingto be delivered to the cooling source and fan 41 and 42 via ducts 102.In this embodiment, the central controller 31 is programmed to comparethe temperature of the outside air as measured by a remote temperaturemeasuring device (not shown) to the thermostat setpoint of the zonerequesting cooling from the system. If the outside temperature is coolerthan the thermostat setpoint, the controller closes return-air vent 9and opens return-air vent 105, opens the vent 10, and turns on the fan42, so that outside air is delivered to the zone covered by vent 10.This configuration is cooling the room without turning on the coolingsource function and thus saves considerable energy. Vents 11 and 12 arekept closed because those zones need no cooling. Depending on thetemperatures inside and outside the building and in particular in thezones requesting cooling, the controller may be further programmed tomix inside and outside air by opening each of vents 9 and 105 partially,to a chosen ratio.

It will be appreciated by persons skilled in the art that the disclosureis not limited to what has been particularly shown and described hereinabove. In addition, unless mention was made above to the contrary, itshould be noted that all of the accompanying drawings are not to scale.A variety of modifications and variations are possible in light of theabove teachings, which is limited only by the following claims.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed herein above. In addition, unless mention was made above tothe contrary, it should be noted that all of the accompanying drawingsare not to scale. A variety of modifications and variations are possiblein light of the above teachings without departing from the scope andspirit of the invention, which is limited only by the following claims.

What is claimed is:
 1. A building air heating, cooling and airconditioning (HVAC) system, comprising: a plurality oftemperature-controlled zones, each zone with at least one motorized airventilation port; at least one of a heating source and a cooling source,the at least one of the heating source and the cooling source includinga fan fluidly connected to the ventilation ports with air ducts; aplurality of zone temperature sensors source positioned to measure theair temperatures in the plurality of temperature-controlled zones; atleast one return-air port fluidly coupled to at least one of the heatingsource and the cooling source; a controller in communication with theplurality of motorized air ventilation ports, the plurality of zonetemperature sensors, and the at least one of the heating source and thecooling source, the controller including: a sensor interface configuredto communicate with the plurality of temperature-controlled zones; aplurality of sensors configured to receive zone temperature sensor data;a monitoring module configured to monitor the zone temperature sensordata in substantially real-time; a trigger module configured to generatea trigger signal when the zone temperature sensor data is different froma predefined zone temperature sensor threshold value; a ranking moduleconfigured to rank the plurality of temperature-controlled zones basedat least on the difference between the real-time zone temperature andthe predefined zone temperature sensor threshold value; an actuatormodule configured to communicate with the trigger module and the rankingmodule and configured to generate control signals to: adjust the openingand closing of the plurality of air ventilation ports according to therankings of the temperature-controlled zones; and activate the at leastone of the heating source and the cooling source and the fan.
 2. Thesystem of claim 1, wherein the fan of the at least one of the heatingsource and the cooling source is activated by a control signal from thecontroller independently from activating the respective heating andcooling function of the at least one of the heating source and thecooling source.
 3. The system of claim 1, where the controller is inwireless communication the plurality of motorized air ventilation ports,the plurality of zone temperature sensors, and the at least one of theheating source and the cooling source.
 4. The system of claim 1, whereinthe at least one return-air vent fluidly couples outside air to the fanthe at least one of the heating source and the cooling source.
 5. Thesystem of claim 1, wherein the motorized ventilation ports are adjustedby the controller to be at least one of closed, fully opened, andpartially opened.
 6. The system of claim 1, wherein at least one of thereturn-air ports is motorized and controlled by the controller to be atleast one of open, closed, and partially open.
 7. A controller forcontrolling a building air heating, cooling and air conditioning (HVAC)system, that communicates with a plurality of motorized air ventilationports, a plurality of zone temperature sensors, and an on-demand heatingor cooling source including a fan, the controller comprising: a sensorinterface configured to communicate with the plurality of zonetemperature sensors to receive zone temperature sensor data; amonitoring module configured to monitor zone temperature sensor data insubstantially real-time; a trigger module configured to generator atrigger signal when the zone temperature sensor data is different frompredefined zone temperature sensor threshold value; a ranking moduleconfigured to rank the plurality of temperature-controlled zones basedat least on the difference between the real-time zone temperature andthe predefined zone temperature sensor threshold value; an actuatormodule configured to communicate with the trigger module and the rankingmodule and generates control signals to: adjust the opening and closingof the plurality of air ventilation ports according to the rankings ofthe temperature-controlled zones; and activate the at least one of theheating source and the cooling source and the fan.
 8. The controller ofclaim 7, wherein the fan of the at least one of the heating source andthe cooling source is activated by a control signal from the controllerindependently from activating the respective heating and coolingfunction of the at least one of the heating source and the coolingsource.
 9. The controller of claim 7, where the controller is inwireless communication the plurality of motorized air ventilation ports,the plurality of zone temperature sensors, and the at least one of theheating source and the cooling source.
 10. The controller of claim 7,wherein the at least one return-air vent is fluidly couple outside airto the fan of the at least one of the heating source and the coolingsource.
 11. The controller of claim 7, wherein the motorized ventilationports are adjusted by the controller to be at least one of closed, fullyopened, and partially opened.
 12. The controller of claim 7, wherein atleast one of the return-air ports is motorized and controlled by thecontroller to be at least one of open, closed, and partially open.
 13. Amethod of controlling a zoned, building air heating, cooling or airconditioning system to control the temperature environment of theindividual zones without the use of on-demand heating and coolingsources that consume energy, the method comprising: collecting data froma plurality of zone temperature sensors; monitoring the temperaturesensor data in substantially real-time; generating a trigger signal whenzone temperature sensor data is different from predefined zonetemperature sensor threshold values; ranking the plurality oftemperature-controlled zones based at least on the difference betweenthe real-time zone temperature and the predefined zone temperaturesensor threshold value; adjusting the opening and closing of a pluralityof motorized air ventilation ports in the zones according to therankings of the zones, and activating a fan that moves air between thezones that have open ventilation ports, when the trigger signal ispresent.